How to Choose Between PLC & FBT Fiber Optic Splitters?

In FTTx and PON architectures, fiber optic splitter is an important component to share the optic network with multiple users. The basic principle of fiber optic splitter is to split one optic light beam into several parts at a certain ratio. According to different manufacture technologies, fiber optic splitters can be divided into PLC splitter and FBT splitter. You may wonder the differences of the two splitter types when making a choice between them. This article aims at helping you to understand their distinctions and make better decisions.

fiber optic splitters

Basics of PLC & FBT Splitters
What Is PLC Splitter?

PLC refers to planar lightwave circuit. As a micro-optical device, PLC splitter uses an optical chip to split the input signal into various outputs. At the edge of the chip, there is a light circuit in ribbon form mounted on a carrier and fibers. PLC splitter typically adopts silica glass as the material of lightwave circuit and accepts different types of polished finishes. The substrate, waveguide and lid are three basic layers of the PLC splitter. For different applications, PLC splitters can be further categorized into different types including bare PLC splitters, blockless PLC splitters, ABS PLC splitters, LGX box PLC splitters, mini plug-in type PLC splitters, tray type PLC splitters and 1U rack mount PLC splitters.


What Is FBT Splitter?

FBT, or fused biconic taper uses the traditional technology to fuse several fibers together closely. Fibers are aligned by heating for a specific location and length. Fusion process will not stop until the parameters of the fibers reach the required standards. Since fused fibers are very fragile, they are protected by a glass tube made of epoxy and silica powder. Then a stainless steel tube covers the inner glass tube and is sealed by silicon. FBT splitter with ABS box is also widely used for different applications.


Differences Between PLC & FBT Splitters

PLC and FBT splitters may look similar to each other, yet they still have many differences when it comes to actual applications. Here will compare them from several aspects.

Splitting Ratio

Splitting ratio is decided by the inputs and outputs of a splitter. A PLC splitter is available with the splitting ratio of 1:64, which means one light beam can be separated into 64 splits at a time. However, FBT splitter is typically used for networks requiring the splitter configuration of less than 4 splits. When its splitting ratio is larger than 1:8, more errors will occur and cause higher failure rate. Thus, FBT splitter is more restricted to the number of splits in one coupling.

Wavelength Range

PLC splitter has a wider operating wavelength ranging from 1260 nm to 1620 nm, thus it can be applied to most of the applications in FTTx and PON networks. On the contrary, FBT splitter has a limitation only to be used for 850nm, 1310nm and 1550nm wavelengths. This leads to the unavailability of FBT splitter on other wavelengths.

Temperature Dependent Loss

Temperature dependent loss (TDL) of the splitter is affected by the manufacturing process and the sensitivity of device. Once the working temperature of splitter is out of range, insertion loss will increase and influence the performance of splitter. PLC splitter is able to work at the temperature of -40 to 85 Celsius degrees while FBT splitter can only work at -5 to 75 Celsius degrees.


Owing to the complicated manufacturing technology of PLC splitter, its cost is generally higher than the FBT type. If your application is simple and short of funds, FBT splitter is definitely a cost-effective solution.


In this article, some differences between PLC and FBT splitters are introduced to help you choose the most suitable one for your network. Overall, PLC splitter has better performance and less limitations, but FBT splitter is less expensive to save more for the budgets. If you are still uncertain which one to choose, please consult a professional for help.

Differences Between FBT Splitter and PLC Splitter

Nowadays, with the further popularization of the optical fiber communication, fiber optic splitter plays an increasing significant role in many of today’s optical network topologies. Although there are variations of splitter types, the two most commonly deployed splitters are FBT (Fused Biconical Taper) splitter and PLC (Planar Lightwave Circuit) splitter. So, when you deploy your network, what kind of splitter you should choose may be a problem for you. And in order to solve this problem, this paper will give you a detailed introduction of differences between FBT splitter and PLC splitter.

Definition of FBT Splitter and PLC Splitter

Before you get to know the features of them, first you should know what them are. Next, each splitter will be introduced.

FBT Splitter – FBT is a traditional technology that two fibers are typically twisted and fused together while the assembly is being elongated and tapered. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube, typically 3mm diameter by 54mm long. FBT splitters are widely accepted and used in passive optical networks, especially for instances where the split configuration is not more than 1×4. The slight drawback of this technology is when larger split configurations such as 1×16, 1×32 and 1×64 are needed.

PLC splitter – A PLC splitter is a micro-optical component based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability. It is manufactured using silica glass waveguide circuits that are aligned with a V-groove fiber array chip that uses ribbon fiber. Once everything is aligned and bonded, it is then packaged inside a miniature housing. PLC Splitter has high quality performance, such as low insertion loss, low PDL (Polarization Dependent Loss), high return loss and excellent uniformity over a wide wavelength range from 1260 nm to 1620 nm and have an operating temperature -40°C to +85°C.

Feature Comparison of FBT Splitter and PLC Splitter

In the past few years, splitter technology has made a huge step forward, especially the PLC splitter technology. This situation resulted in that PLC splitter has become a higher reliable type of device compared to the traditional FBT splitter. Although being similar in size and appearance, the internally technologies behind these types vary, thus giving service providers a possibility to choose a more appropriate solution.

Operating Wavelength – As is mentioned above, PLC splitter can provide a range of operating wavelength from 1260 nm to 1620 nm. But FBT splitters only support three wavelengths (850/1310/1550 nm) which makes these devices unable to operate on other wavelengths.

Operating Temperature – Commonly, FTB splitter is to a high extent temperature sensitive, providing a stable working range of -5 °C to 75 °C. While PLC splitter operates at wider temperature range (-40 °C to 85 °C), allowing its deploying in the areas of extreme climate.

Split Ratio – The split ratio of FBT splitter is 1:8 and it can be higher with higher failure rate. The split ratio of PLC splitter can go up to 64, which is equal to all branches, thus providing a high reliability.

Cost – FBT splitter is made out of materials that are easily available, for example steel, fiber, hot dorm and others. All of these materials are low-price, which determines the low cost of the device itself. PLC splitter manufacturing technology is more complex. It uses semiconductor technology (lithography, etching, developer technology) production, hence it is more difficult to manufacture. Therefore, the price of this device is higher.

FBT and PLC splitter feature comparison


In a word, Compared with FBT splitter, the capacity of PLC splitter is better, but costlier than the FBT splitter in the smaller ratios. You can choose it according to your requirements. Fiberstore offers both FBT splitter and PLC splitter with good quality and low price. Whether in FTTx systems or in traditional optic network, Fiberstore splitter can help you to maximize the functionality of optical network circuits.

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PON Splitters—An Important Role in FTTH Networks

Created by the Full Service Access Network (FSAN) working group, the Passive Optical Network (PON) is a group of technologies that put Fiber to the Home (FTTH) into reality. It consists of a central office node optical line terminal (OLT) at the service provider’s office and a number of optical network units (ONUs) near the end users. A single PON network interface can be shared among many subscribers through the use of PON splitter which contains no electronics and use no power.

Passive Optical Splitter & FTTH

For the FTTH network designer, one of the key parameters is the achievable span between the central office and the subscribers (the maximum optical budget allowed in the system). As a part of the optical budget, the PON splitter is the most demanding component in terms of losses. Thus every FTTH system vendor is advised to use a PON splitter with the lowest level of insertion loss and maximum uniformity.

PON Splitter in FTTH Networks

Sharing one expensive laser with up to 32 homes, a PON splitter takes one input and splits it to broadcast to many users, cutting the cost of the links substantially. Furthermore, since PON splitters are bi-directional devices, signals can be sent downstream from the central office, broadcast to all users, and signals from the users can also be sent upstream and combined into one fiber to communicate with the central office.

The PON splitter can be one unit in a single location or several splitters cascaded. To reduce the amount of fiber in a network, cascaded splitters can be used by placing splitters nearer the user. This is usually done when houses being served are clustered in smaller groups.

Most PON splitters are 1×32 or 2×32 or some smaller number of splits in a binary sequence (2, 4, 8, 16, 32, etc.). Adding considerable loss to an FTTH link, Splitters limit the distance of an FTTH link compared to typical point-to-point telco link. To solve this problem, every house needs to be connected to the local central office with single mode fiber through a fiber splitter.

Two Kinds of PON Splitters

The fused biconical tapered (FBT) coupler and the planar lightwave circuit (PLC) splitter are two main kinds of technical approaches to solving the signal splitting issues in an FTTH system. FBT couplers, also known as FBT WDM splitters, are traditional fused splitters which feature competitive price. PLC splitters are based on the PLC technology, which has compact sizes and suits for density applications.

PON splitter-1x2 FBT splitter
1x2 Bare Fiber PLC splitter

PON splitter in the PON system allows a signal transmitted over a single optical fiber from the telephone exchange office to be shared with multiple users, hence reducing the cost of every subscriber. Nowadays, the PON system has expanded extensively as an optical network in the construction of FTTH. Different manufacturers produce a large amount of PON splitters which have different functions. FS, which is one of the optical network products suppliers, provides both PLC splitters and FBT couplers for Ethernet passive optical network (EPON)/Gigabit passive optical network (GPON) system.

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Differences Between FBT Splitter and PLC Splitter

Present Great Developments and Expections for FTTH

FTTH, Fiber to the home, you know. It provides the final customer access technology. There is a situation that fiber optic cables are extended to the ONU (Optical Network Unit) based on the customer’s premises, it also supply the customer virtually unlimited bandwidth for all the applications such as video, voice and high speed data and the speed can reach up to 1G per customer. Related passive optical product: PLC splitter . And the FTTH is future proof, it becomes the only one technology that can meet the requirements for such high bandwidth, the FTTH architecture is shown at the Figure.


We know ONU is required for each client rather than for a group of up to several hundred customers. FTTH is not cost effective at this time, and is dependent upon advances in technology to provide a more cost effective bandwidth on fiber optic cables and effective ONU technology.

Well, FTTH will be many people’s preference. We can know after comprehensive knowledge that the easiest way to provide FTTH is to use passive 1:N optical splitter to divide the optical bandwidth roughly equally between the N customers. Alternatively, a single fiber can also apply for both directions od transmission using wavelength division multiplexing (WDM). The splitting of the optical power among many consumers in a PON (Passive Optical Network) has significant optical power budget.

Recent years FTTH has some developments, such as a proposal for the creation of a GNDG (gigabit national data grid), it can overcome the bandwidth communications requirements for the future and the proposal also allows the use of the alternative access technologies, already discussed, such as XDSL, coax or wireless to provide service at lower data rates. However, interfacing to such solutions may well cost nearly as much as the final FTTH infrastructure. In fact, WDM with optical splitters or optical amplifiers are the main technologies required to implement such a FTTH network. Now WDM systems can provide bandwidths of 40G per fiber, use 16 wavelengths at 2.5 G each, and hope it can reach 100 rerabits in the next 5 years.

Different Functions of Some Types of Fiber Optic Splitter

Functions of various fiber optic splitter types are different. First, we’ll learn what is optical splitter.

Basic knowledge of Optical Splitter

Passive optical networks are characterized by the “splitting” of the optical fiber one or more times in the field, resulting in the sharing of the optical fiber amongst multiple users. The fiber in a PON is typically shared with 16 to 32 users. Hence the bandwidth of the fiber originating at the CO/HE is shared among a group of users. The splitting of the network is accomplished by an optical splitter. These splitters can split the fiber 2 to 32 times and, by their nature, introduce inherently high losses in the network. Therefore, their use is limited due to the power budget consideration of the network.

Increasing network reliability. A single 1 x 32 splitter has less loss than 1 x 2 and 1 x 16 or 1 x 4 fiber splitter and 1 x8 cascaded splitters or any combination of 1 x 16 or fiber splitter 1 x 4 and 1 x8 cascaded splitters in the network. With the evolution of optical networks, the need for multiple distributions of optical signals is crucial. For this application TELNET, S.A. offers its range of single mode and multimode fiber splitter. These couplers or splitters are used to split the input signal into N output branches with minimum loss.

Centralized Split

Functions of Different Fiber Optic Splitter Types

PLC splitter

PLC splitter is one of fiber optic splitter types, and just its full name is planar lightwave circuit splitter, and it is made of silica optical waveguide technology. It has a good channel to channel uniformity, high reliability and small size which ranges of wide operating wavelength. and is widely used in PON networks to realize optical signal power management. And We Fiberstore provide a series of 1 x N and 2 x N splitters that all meet GR-1209-CORE and GR-1221-CORE and are certified by TLC for network development.

Fused Fiber Splitter

A fiber fused coupler is one of the most popular passive components for wavelength multi/demultiplexing or branching/combining of optical signal. They are used to split optical signals between two fibers, or to combine optical signals from two fibers into one fiber. Fused couplers do suffer from some disadvantage. Multimode fused couplers are mode dependent. Single fused couplers only transmit one mode, so they do not suffer from mode dependency. However, they are highly wavelength dependent. A difference in wavelength of which the fused fiber coupler will be used.

FS fused fiber couplers are available in a range of wavelengths, fiber sizes, and splitting ratios. Standards configurations are one by two and two by two couplers. N by M couplers, such as one by three, or one by four and so on are also available on request.

FTTH splitter

As for another passive optical splitter, FTTH splitter, these couplers/splitters are very often used in CATV networks. The Plastic splitter box is used for fiber cable and fiber communication equipment connection. It has redundant space for pigtails and adapters after up to 48 fusion splicing. Suitable for the ABS or LGX packed splitters to protect the connection between fiber cable and pigtails. Mainly for FTTH projects to be wall mount or rack mount fiber splitter, is realizing the function of fiber splitter, splicing, distribution and FTTH cable configuration.

fiber optic splitter types-FTTH splitter


As mentioned above, different fiber optic splitter types have different functions. FS provides all the kinds of optical splitters, and they all meet the national standard of the optic network, and more than to say, It is doing big sales on many of their optical products.

Related Articles:
How Much Do You Know About PLC Splitter?
Differences Between FBT Splitter and PLC Splitter